Production of high-frequency embryogenic calli from integuments of immature seeds ofCarica Papaya, L.

SummaryTissue culture conditions that enable production in Carica papaya L. of high frequency embryogenic calli on the internal integuments of immature seeds are defined: The explants have to be removed three or four months after anthesis and cultured on the three monthly successive media: Ml-1 (2,4-D 9 µM), M2 (2,4-D 0.09 µM + KIN 1 µM), M3 (M2 + ABA 0.5 µM). A histocytological study during culture proved that friable calli capable of producing embryos were of maternal origin. This procedure thus permits the cloning of adult plants.